The present application claims the benefit of priority from Danish patent application No. PA 2001 00102 filed on Jan. 19, 2001.
This invention relates to skylights or roof windows comprising a main frame structure for stationary connection with supporting means of a roof structure, and a window frame structure carrying a glazing element, the main frame and window frame structures having respectively a plurality of members, each of which members extends in a longitudinal direction between a first and a second end; wherein said window frame structure is connected with the main frame structure by means of at least one hinge connection at a respective first member of the main frame and window frame structures to allow the window frame structure to be pivoted about a pivot axis parallel with the longitudinal direction of said first members with respect to the main frame structure to an opening angle, said hinge connection being disengageable to allow the window frame structure to be removed from the main frame structure, said at least one connection including at least one pair of first and second connecting members connected with the main frame and window frame structure, respectively, a securing device being provided for maintaining the engagement between the connecting members of said pairs within a predetermined range of the opening angle of the window frame structure.
For reasons of installation conditions, it is often desirable to install such windows in an inclined roof surface by initial securing of the main frame of the window, from which the glass-carrying window frame has been detached, to the roof supporting structure. Following this operation the window frame structure is hatched on to the main frame structure by bringing the connecting members of the window frame into engagement with the connecting members of the main frame. Evidently, it is essential that the window frame structure is properly secured against unintentional removal from the main frame structure.
In its most simple form such securing may be achieved by making the connection between the connecting members of the main frame structure and the window frame structure permanent following the initial engagement operation.
However, it is often desirable to retain the possibility of disengaging the connection between the window frame and the main frame, eg. for maintenance purposes.
WO 93/11332 discloses a window, in which securing means are provided for retaining the engagement between the connecting members of the window frame and the main frame, said means comprising a block which may be displaced in a groove in a side member of the window frame and which may serve partly as an anchoring element for a locking member fastened in the main frame structure of a fixed window, partly for releasable coupling with an operating member of a window operator in the case of an openable window. This solution suffers from the drawback that the securing means are dependent on a particular design of the operator in order to provide proper functioning.
In the window disclosed in WO 98/22685 the securing means are constituted by holding means fastened to the side members of the window frame structure at a comparatively short distance from the pivot axis. The holding means include blocks with part-cylindrical guide surfaces having an axis in the pivot axis of the hinge. Due to the position close to the pivot axis, these blocks are subjected to rather heavy load during opening of the window frame.
It is an object of the invention to provide a roof window in which the conditions with respect to initial mounting and subsequent dismounting of the window frame structure are improved even further.
It is a further object of the invention to provide a roof window which has a less complex design compared to prior art window designs.
These objects are met by the provision of a roof window of the initially stated kind, in which said securing device includes at least one torsion member positioned at a respective end of said first members of the main frame and window frame structures, said at least one torsion member being torsionally biased in the opening direction of the window frame structure with respect to the main frame structure and including engagement means for engagement with corresponding engagement means positioned at a distance from said pivot axis along a second window frame member adjacent said first member of the window frame structure within said predetermined range of the opening angle.
By the incorporation of a torsion member which follows the movement of the window frame structure during opening of the window within the predetermined range of the opening angle, in which the securing device is active, the activation and deactivation of the securing device is effected automatically. In addition to providing security against unintentional removal of the window frame, the torsion member assists the pivotal movement of the window frame structure from the closed position to a ventilating position.
In another aspect of the invention a securing device for maintaining the engagement between connecting members of a main frame structure and a window frame structure of an openable roof window within a predetermined range of the opening angle of the window frame structure is provided, said securing device including at least one torsion member to be connected with of the window, said at least one torsion member being torsionally biased in the opening direction of the window frame structure with respect to the main frame structure and including engagement means for engagement with corresponding engagement means to be positioned on the window frame structure.
Further details and advantages will readily be appreciated from the appended drawings and the detailed description to follow.